Chemistry: Atoms, Molecules, and Chemical Formulas Worksheet

What is the smallest unit of an element that maintains its chemical properties?

• A molecule

• An atom

• A compound

• An electron

Which of the following best describes a molecule?

• A single atom of any element

• Two or more atoms bonded together

• A proton and neutron together

• The nucleus of an atom

The chemical formula H2O indicates that a water molecule contains:

• One hydrogen atom and two oxygen atoms

• Two hydrogen atoms and one oxygen atom

• Two oxygen atoms and one hydrogen atom

• One hydrogen atom and one oxygen atom

What does the subscript number in a chemical formula represent?

• The atomic number of the element

• The atomic mass of the element

• The number of atoms of that element

• The charge of the element

Which of the following is an example of an element?

• Water (H2O)

• Table salt (NaCl)

• Gold (Au)

• Carbon dioxide (CO2)

In the chemical formula CO2, what does the "2" indicate?

• a. Two carbon atoms

• b. Two molecules of carbon dioxide

• c. Two oxygen atoms

• d. The charge on the oxygen

How can you identify the number of different elements in a chemical formula?

• Count the total number of atoms

• Count the different capital letters

The chemical symbol FeFe represents:

• Fluorine

• Iron

• Francium

• Fermium

In the periodic table, what information helps you identify the correct chemical symbol?

• The element's color

• The element's atomic mass

• The element's atomic number

• The element's physical state

Which represents a compound?

• O2O2

• NaNa

• NaClNaCl

• HeHe